Amalgamator



Aug. 13, 1 e. c. CRANGLE AMALGAMATOR Filed Aug. 20, 1938 INVENTOR Kim/yef fraqg BY Mu. fin.

ATTORNEYS Patented Aug. 13, 1940 2,211,10 7 AMALGAMATOR George C.Crangle', San Franciscb; Calif. Application August 20, 1938, Serial No.225,884 7 2 Claims. (c1.-209-' 591 This invention relates generally toapparatuses for recovering gold'from gold bearing material, particularlythe material of the kind usually known as pulp. More specifically, theinvention relates toamalgamators in which the recovery is made bysubjecting the pulp to mercury.

One object of the invention is to provide an amalgamator which iscompact and simple in construction and which is at the same timereadilyaccessible for removing amalgamated gold.

Another object of the invention is to provide an amalgamator which ismore efiicient than devices heretofore known and which will operate withthe minimum of attention between the times at which the gold amalgam isremoved.

While the amalgamator is relatively small and compact, it is soconstructed that the pulp is subject to a large surface of mercury ormercury amalgam as it passes through the apparatus, in addition to whichthe mercury and the pulpare moved in such a manner as to increase theamalgamating effect. I

With the foregoing and incidental objects in view, the inventionconsists in a novel construction and relation of parts, an embodiment ofwhich is hereinafter'described with reference to the drawingaccompanying and forming a part of this specification.

In said drawing:

Fig. 1 is a partial top plan view of anamalgamator embodyingtheprinciples of the invention with upper portions of some of the partsbroken away to expose lower ones to view.

Fig. 2 is a section on the line 2-2 of Fig. 1.

The apparatus comprises a shaft l0 which may be driven in any suitableway as by a pulley drive or by a gear I I attached to the shaft andmeshing with another gear driven by any suitable prime mover.

The invention contemplates a series of successively acting dams l2, l3,l4, l5 and 16. Any number of these clams may be used, but in the drawingfive (5) are shown. These dams may be supported in any desired way but,as a matter of convenience, construction and assemblage, they are, withone exception noted later, the rims of copper pans which have theirexposed surfaces amalgamated. In Fig. 1 the largest pan I! is the lowestone and the others are successively imposed upon this larger pan and allof them are then clamped together on the upper end of the shaft II] by anut [8 having a conical interior surface coresponding with the shape ofthe contiguous face of the top one of the pans.

As shown in the drawing, the dams or rims of the pans are" of graduallyincreasing depth from the top or sh'allow'e'st pan to the lowest ordeepest Concentric to the shaft I0 is a hopper 2| which receives thepulp from the source of supply and deposits itwithin the upper dam I2.The hopper is provided with legs '22 which will support the hopper inposition upon the dam l2. Inserted between the dams arebafiles 23 ofamalgamated material, each of the baffles having a plurality of postsbrother supports 24 which rest upon the dams and provide a 'clearancebetween the dams and between the edges of the bafile plates and thebottoms of the pans.

The rim 25 of the largest or bottom pan does not serve as a dam, thateffect being obtained by a member 26 which is constructed somewhat inthe nature of the bafiies 23 and has supports 2? resting on the rim'ofthe pan. The rimof the. lower pan also has an outwardly extending flange28 which cooperates with a flange 29 on the member l6 to form an outletfor a. purpose herei'nafter stated.'

The assemblage of parts on the shaft It makes what may, for convenience,be referred to as a unitary structure rotating with the shaft when theshaft is driven or turned. The bearing support for the shaft,represented conventionally at 33, is so constructed as to confine theshaft to rotation on an axiswhich is inclined with respect to a verticalline. Asthe different parts of the assemblage are concentric-to'theshaft, this re-' sults in the dams and the bafiles being rotated inplanes which are inclined with reference to horizontal; Behind each ofthe dams is a supply of mercury which is sufficient to amalgamate goldcarried by the pulp and also serve to feed the pulp from one dam to thenext lower dam in succession until the pulp is pushed out at the lowerpart of the assemblage. The height of the mercury is indicated by brokenlines 34 behind the dams and, as will be seen, the mercury is nearer theedge or top of each of the dams at the one side (the right-hand side inFig. 2) than at the other side.

The pulp entering through the hopper 2! will be admitted to theassemblage at what may be termed the lower side of the mercury or highside of the rotating assembled unit; that is to say, above the level ofthe mercury in the top pan and behind the dam I2. The relation betweenthe lower edge of the hopper and the mercury. is such that there is acrescent-shaped opening at 35 which allows the pulp to flow out over themercury behind the dam l2 and on the upper face of the dam. The otherside of the hopper is submerged in the mercury so that the pulp cannotenter from that side. However, the crescent-shaped opening 35 is alwayspresent and the flow of the pulp to the first dam is continuous.

Owing to the inclination of the shaft ID and corresponding tilting ofthe dams, the mercury behind the first dam will act upon the pulp tofeed it over the edge of the dam and against the upper surface of thebafile 23. The pulp will flow over this bafiie and against the mercuryand will be allowed to escape from the baflle and into contact with thedam 13 as the unit makes about a half turn; that is, when the flow ofthe mercury has cleared the lower edge of the baffle, as shown at theleft in Fig. 2. This same feeding of the pulp occurs from one dam to thenext successive dam until a continuous flow of material is establishedbut with what may be termed an intermittent delivery over the edges ofthe dams.

It is preferred to have enough mercury back of the rim 25 of the loweror bottom pan to form a seal, as shown at the left of Fig. 2, so thatthe remaining pulp will be delivered over the upper surface of themember [6. This member [6 is of amalgamated material and will do itspart in recovering gold.

The exit between the flanges 28 and 2Q is to permit mercury to escape inthe event that something abnormal occurs in the operation of the deviceand beneath the lower point (at the right of Fig. 2) a tray orreceptacle of any kind may be stationed to catch any mercury that may beaccidentally displaced from the unit.

From the foregoing it is clear that, while the unit is comparativelysmall and is quite compact in its construction, the pulp is neverthelesssub jected to a long path of travel through the apparatus and is workedby the mercury and over the amalgamated surfaces of the unit in such amanner as to give a very efficient contact as well as agitation of thepulp, thereby giving a very high percentage of gold recovery. Inaddition, owing to the great extent of amalgamated surface to which thepulp is exposed, the apparatus can be operated at comparatively lowspeed, preferably from 10 to 15 R. P. M. This contributes verymaterially to operation over a relatively long period of time withoutany danger of causing flouring of the mercury; that is to say, theapparatus of this application with its great exposure of pulp to mercuryis effective at low speeds without deterioration or loss of mercurywhich occurs with amalgamators operated at high speeds.

While the form of apparatus shown in the drawing and described above isadmirably adapted to fulfill the purposes primarily stated, that formmay be varied in many ways by changing the construction and relation ofparts and it is not the desire to be limited to any extent, except asspecified in the claims which follow.

In removing the gold amalgam, the nut l8 may be removed and the partslifted off in succession to render them accessible, and particularly tomake accessible the corners or angles between the bottoms of the pansand the rims of the pans.

The bafiles 23, while highly desirable, because of the increasedamalgamated surfaces, may be omitted and they may be removed withoutdisassembling the apparatus by shifting them sidewise and then tiltingthem upward from one side so as to clear the dam above them. The hopper2| will, of course, first have been removed.

What is claimed is:

I. An amalgamator comprising a rotatable shaft supported at aninclination to vertical, a plurality of rimmed pans stacked and fastenedon the shaft with adjoining faces of the pans in contact and each ofsaid pans being of a greater diameter than the one above it, and meansfor rotating the shaft whereby, because of the in-- clination of theshaft and pans, pulp is caused to flow over the rim of each pan into thenext lower pan at the low sides of the rims.

2. An amalgamator comprising a rotatable shaft supported at aninclination to vertical, a plurality of rimmed pans stacked and fastenedon the shaft with adjoining faces of the pans in contact and each ofsaid pans being of a greater diameter than the one above it, bafflesconcentric to the shaft and between the rims of the pans, and supportedout of contact with the bottoms of the pans, and means for slowlyrotating the shaft, pans and baiiles as a unit and thereby because ofthe inclination of the shaft, cause the pulp to flow over the low sidesof the rims of the pans and over and under the baflie.

3. An amalgamator comprising a shaft supported for rotation at aninclination from vertical, a set of rimmed pans having conical bottomsand stacked together and secured to the shaft with the upper edges ofthe rims in planes at right angles to the axis of the shaft whereby tohold the pans in a tilted position, battles between and parallel to therims of the pans and supported with their lower edges out of contactwith the bottoms of the pans, mercury in the pans in willcient quantityto cover the lower part of the baffles at the low side of the tiltedpans and have a clearance between the lower edges of the baffles and thebottoms of the pans at the high side of the tilted pans, and means forrotating the shaft and parts assembled thereon.

GEORGE C. CRANGLE.

